Magnetic door closure device

ABSTRACT

THE PRESENT INVENTION RELATES TO A DOOR CLOSURE DEVICE IN WHICH A PERMANENT MAGNET IS ATTACHED TO ONE AND A MAGNETICALLY PERMEABLE MEMBER IS ATTACHED THE RESPECTIVE OTHER ONE OF TWO DOOR MEMBERS MOVABLE RELATIVELY TO EACH OTHER. THE PERMANENT MAGNET IS MOVABLY MOUNTED IN UTS RESPECTIVE MEMBER AND RESILIENTLY URGED IN A DIRECTION OPPOSITE TO THE DIRECTION OF ITS MOVEMENT UNDER THE EFFECT OF THE ATTRACTIVE FORCE BETWEEN THE PERMANENT MAGNET AND THE MAGNETICALLY PERMEABLE MEMBE

May 23, 1972 P. WEIGELT 3,664,699

MAGNETIC DOUR ULOSUIU'J UluV l VX'I Filed March 12, 1970 :1 Shoots-Shout1 F/gi lnrenfan PETER WEIGELT ATTORNEY May 23, 1972 P. WEIGELT MAGNETICDOOR CLOSURE DEVICE 2 Sheets-Sheet 2 Filed March 12, 1970VIII/IIIIII/flrll/l T lnren/ar:

PETER WEIGELT BY ATTORNEY United States Patent 3,664,699 MAGNETIC DOORCLOSURE DEVICE Peter Weigelt, 4521 Bakum 156, Germany Filed Mar. 12,1970, Ser. No. 19,059 Claims priority, application Germany, Mar. 15,1969, P 19 13 330.3 Int. Cl. Ec 19/16 US. Cl. 292-2515 1 Claim ABSTRACTOF THE DISCLOSURE The present invention relates to a door closure devicein which a permanent magnet is attached to one and a magneticallypermeable member is attached to the respective other one of two doormembers movable relatively to each other. The permanent magnet ismovably mounted in its respective member and resiliently urged in adirection opposite to the direction of its movement under the elfect ofthe attractive force between the permanent magnet and the magneticallypermeable member.

BACKGROUND OF THE INVENTION For insulating doors of the kind employed inthe construction of refrigerating chambers, there is the generalrequirement that a high degree of sealing is attained in their closedstate. This necessitates great pressure on any seals maintained betweenthe door and the frame; on the other hand only a small expenditure ofenergy should sutfice for opening and closing the door. Moreover, anydeterioration of the elasticity of this sealing must be balanced by thepressure maintained between parts of the door. Finally, there is therequirement that the assembly of the door fittings must be very simpleand that the fittings do not diminish the insulation qualities of thedoor.

The previously known and conventional spring cam fittings and pressurelever worm drive fittings, as employed for doors of refrigerating orfreezing chambers, do not meet the requirements in respect of ease ofoperation. Furthermore, they must at least in part be accommodatedwithin the body of the door and thereby detract from the insulationqualities of the door. Finally, the known closure fittings requireaccurate work in their assembly, since they exert pressure in only alimited range.

SUMMARY OF THE INVENTION It is an object of the invention to avoid thedisadvantages of the prior art by the application of a conventionalmagnetic door closure, consisting of at least one permanent magnet andone magnetically permeable part which combine to form the closuredevice. Since, however, an applied pressure of approximately 100 poundsis required for hermetically sealing an insulating door of arefrigerating chamber and permanent magnets capable of such performancealready draw the door strongly against the frame even through theopening may still be about one inch wide. It is a particular task of theinvention to provide a novel magnetic closure particularly suitable forrefrigerating and freezing chamber doors, which meets all the mentionedrequirements and is yet easily operable in spite of the strong appliedpressure.

For this purpose, the magnetic door closure device provided by theinvention is characterised by the permanent magnet being mounted to bemovable in the direction of the effective magnetic force and cooperatingwith a resilient element, which is stressed by the motion of thepermanent magnet towards the magnetically permeable member. Thepermanent magnet is preferably provided with a shank carrying a collarand guided by means of these in a recess of a carrier mounted on thedoor, the resilient element being housed in the recess between thecollar "Ice and a cover plate defining the outward boundary of therecess. The resilient element may simply and expediently consist of ahelical spring. It is also expedient for a damping plate of shockabsorbent material such as soft rubber or the like to be mounted at theinner end of the recess to act as an abutment surface for the collar.

In a particularly advantageous embodiment of the magnetic door closureaccording to the invention, two carriers, each provided with a permanentmagnet, are mounted on the insulating door, the carriers beingconstructed to form holders for a door handle extending therebetween andtogether to provide the closure device.

Various other objects and advantages of this invention will become moreapparent from the following description illustrated by the accompanyingdrawing of an embodiment described by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS .FIG. 1 shows a partial view of amagnetic closure device embodying the invention;

FIG. 2 shows a section on the line IIII in FIG. 1;

FIG. 3 shows a section on the line III-III in FIG. 1, in the openedposition, while FIGS. 4 to 6 show corresponding views of the magneticclosure device according to FIGS. 1 to 3 respectively; with the closuredevice in the closed state.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings show that part ofan insulating door 1 which is visible in the proximity of the closuredevice, a frame 2 and a seal 3 by means of which the insulating door 1in its closed state provides hermetical sealing with the frame 2. Amagnetically permeable member 4 consisting of a steel plate or the likeis fastened at the outside of the frame 2 in the range of the doorclosure device.

At the outside of the insulating door 1, there is mounted a carrier 5which projects laterally of the profile of the door and is provided witha recess 6 in a second portion just beyond the edge of the door. Therecess 6 and the carrier 5, which in the closed or near the closed stateof the insulating door 1 face the magnetically permeable member 4 on theframe 2, are provided for the mounting and guiding of the permanentmagnet 7. This permanent magnet 7 is attached to one end of a shank 8,the other end of which is provided with a collar 9 and extends into theinterior of the recess 6. The outer end of the recess 6 is covered by acover plate 10, which is provided with an opening for the shank 8 of thepermanent magnet 7 to pass through. The plate 10 acts as a support orcounter bearing for a helical spring 11, which is located in theinterior of the recess 6 and supported at its other end on the collar 9.The permanent magnet 7 is thus movably mounted and guided in the carrier5, or rather in its recess 6, and cooperates with the spring 11 to movein the direction towards the magnetically permeable part 4 on the frame2, he in the direction of the magnetic door closure force.

As may be seen from the drawings (in particular FIGS. 3 and 6), theillustrative embodiment may be provided with two carriers 5 eachcarrying one permanent magnet 7, the carriers 5 simultaneously formingholders for a door handle 12 extending therebetween and togetherproviding a closure.

When the door and closure device are closed (FIGS. 4 to 6) then thepermanent magnet 7 (or both the permanent magnets 7 of the closuredevice) rests on the magnetically permeable member 4 of the frame 2 anddoes so with the given magnetic force of attraction. In this, the spring11 is lightly compressed and stressed by means of the collar 9 at theend of the shank 8 of the permanent magnet and transmits the attractiveforce of the permanent magnet 7 via the cover plate 10 to tliec'arrierand thereby to the insulating door 1, which is thus hermetically closedunder compression of the seal 3. The spring 11 provides a constantapplied pressure even when the seal 3 has become weakened. On theopening of the door, when the handle 12 of the closure device is beingpulled, the spring 11 is further compressed until a pressure has builtup within it of such a magnitude, that the magnet 7 is pulled away fromthe magnetically permeable plate 4 on the frame 2. In this process, thespring loading is dis charged and the collar 9 provided at the end ofthe shank 8 on the permanent magnet 7 bounces against a damping plate 13of soft rubber or the like at the inner end of the recess 6 in thecarrier 5, so that no disturbing noise is created. Instead of the softrubber plate 13 acting as a damping abutment or in addition thereto, abutter of soft rubber or the like may also be provided on the outer faceof the cover plate 10. In the opened position, the permanent magnet 7and the spring 11 assume the position shown in FIGS. 1 to 3.

The opening of the door can easily be effected with little exertion,since the permanent magnet 7 is not detached with a jerk but by a pullexerted over a path of about one inch, i.e. the extent of thecompression of the spring 11, and then automatically jumps back by meansof the spring force.

It is to be emphasized, that the magnetic closure device according tothe invention is not limited in its application to doors of cooling orrefrigerating chambers, but may with advantage be applied in all casesin which similar conditions exist and similar requirements are to bemet.

It is also to be understood that the invention is not limited to theexemplary embodiment hereinbefore described and shown in the drawings,but that modifications in different aspects are feasible and possible.

I claim:

1. A door closure device, comprising in combination (a) cooperatingclosure members on mutually facing surface portions of a movable doorand a door frame, respectively;

(b) a magnetically permeable member attached to one of said cooperatingmembers;

4 (0) guide means mounted in fixed relationship to the respective otherone of said cooperating members. (d) a permanent magnet movably retainedby said guide means; and (e) resilient means urging said permanentmagnet (i) in a direction opposite to the direction of the attractiveforce between said magnetically permeable member and said permanentmagnet; and (ii) to a degree insufficient to overcome the attractiveforce present when the door is closed; (f) two carrier means mounted onsaid door and connecting said guide means to said respective other oneof said cooperating members; (g) holders extending one from each of saidcarrier means; (h) a door handle located intermediate said holders; (i)wall portions of said carrier means forming a recess of said guidemeans; (i) a plate covering said recess at the outer end thereof; (it) ashank attached at one end thereof to said permanent magnet and extendingthrough an aperture in said plate into said recess; and (l) a collarprovided at the respective other end of said shank and located withinsaid recess, said resilient means being located between said collar andsaid plate.

References Cited UNITED STATES PATENTS 3,221,375 12/1965 Lewis 292-2615X 3,400,964 9/1968 Baermann 292-2515 3,492,037 1/1970 Hutchinson-.292-251.5

FOREIGN PATENTS 1,172,275 10/1958 France 335-285 1,180,547 12/1958France 292-2515 286,640 2/1953 Switzerland 292-2515 GEORGE F. MAUTZ,Primary Examiner E. J. MCCARTHY, Assistant Examiner

